Grinding disc



June 4, 1968 F, oA SHOEMAKER 3,386,214

GRINDING DISC Filed sept. 1, A1965 o o o o o o o o o o 'o'.''ffff- ,f

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A rroR/vsys United States Patent O 3,386,214 GRINDING DISC Frank 0. Shoemaker, Palos Park, Ill., assignor to Titan Abrasives Company, a corporation of Illinois Filed Sept. 1, 1965, Ser. No. 484,211 3 Claims. (Cl. 51--356) ABSTRACT OF THE DISCLOSURE An abrasive grinding disc having a side grinding surface and a peripheral edge with a coolant opening being provided adjacent the center of the disc, a number of first coolant passages extending from this center opening toward but short of the peripheral edge and at the end of each rst coolant passage, a second coolant passage arranged transversely to its first passage to receive coolant therefrom with all coolant passages having open sides at the grinding surface and all extending in essentially straight lines.

This invention relates to an abrasive grinding disc.

As disclosed in prior Patent 2,734,813, assigned to the same assignee as the present invention, grinding discs, wheels and the like are customarily manufactured from abrasive grains held in a solid mass by a resin binder. During the grinding operation it is customary to feed coolant liquid which is usually water or water and a water soluble oil to the grinding face at the center thereof with the coolant spreading over the grinding surface to reduce, the temperature and carry away particles from both the abrasive article and the work being ground.

One of the features of this invention is to provide an improved abrasive grinding disc having means thereon including a plurality of coolant passage means in the form of channels and arranged in a particualr manner in order to aid in distributing the coolant from the center of the grinding disc substantially uniformly over the surface thereof even in the areas adjacent the disc periphery, and without dangerously weakening the disc.

Other features and advantages of the invention will be apparent from the following description of one embodiment thereof taken in conjunction with the accompanying drawings. Of the drawings:

FIGURE 1 is a semi-diagrammatic side elevational view partially broken away of a disc grinder utilizing a pair of grinding discs each embodying the invention.

FIGURE 2 is a diagrammatic elevational view showing the continuous feed of a series of rings through a pair of discs for grinding the sides of the rings.

FIGURE 3 is a front elevational view of the side grinding surface of one of the discs shown in FIGURE 1.

FIGURE 4 is a fragmentary enlarged sectional View taken substantially along line 4 4 of FIGURE 3.

In FIGURE 1 there is disclosed a fragmentary semidiagrammatic elevational view of a disc grinder employing a pair of spaced grinding discs arranged vertically each mounted on a circular steel backing plate 11 in the customary manner. Each disc has a grinding surface 12 facing and substantially parallel to the surface of the opposite disc. Each disc is also provided with a circular peripheral edge 13. In Aorder to rotate the discs 10 so as to grind work pieces such as rings illustrated at 14 that are passed in series between the discs and in contact with the surfaces 12, each backing plate 11 is -mounted concentrically on a hollow spindle 15 (of which only one is shown) that is rotatable about a horizontal axis.

Each spindle 15 is hollow so that coolant liquid of the customary type which is normally a soluble oil and water can be forced toward each disc through the hollow interior 16 of the spindle as indicated by the arrow 17 ice in FIGURE 1. Each disc 10 is provided with a coolant opening 18 (FIGURE 3) adjacent its center so that the coolant will tiow to the grinding surface 12.

In order to aid in distributing the liquid coolant over the grinding surface 12 there is provided in each disc a plurality of first coolant passage means illustrated at 19 formed in the disc and extending from the center opening 18 toward but short of the peripheral edge 13. In the illustrated embodiment these iirst passages extend radially from the center opening 18 so that coolant will bek forced outwardly in these passages by the centrifugal forces set up by the rotating disc.

The disc also includes a plurality of second coolant passages 20 with each being arranged at the outer end of a first passage 19 and extending transversely to its passage 19. In a preferred construction coolant passages 20 and therefore the outer ends of passages 19 are spaced substantially equal distances from the disc edge 13 and preferably each is arranged on a chord of the disc. Each passage 20 preferably extends at right angles to its passage 19 and has its opposite ends substantially equally spaced from the passage 19.

In addition, the illustrated disc contains a plurality of customary radial relief passages 21 each extending inwardly a short distance from the peripheral edge 13. In the illustrated embodiment each passage 21 is arranged generally symmetrically between an adjacent pair of a first passage 19 and corresponding second passage 20.

In the illustrated embodiment which is the preferred construction the outer ends of the first coolant passages 19 describe a circle substantially concentric with the peripheral edge 13 of the disc. The second coolant passages 20 are approximately tangent to this imaginary circle and thus are spaced substantially equal distances from the edge 13. Spaced perforations 23 are arranged substantially symmetrically throughout the disc. The passages 19, 20 and 21 and perforations 23 open to the surface 12 of the disc 10 as shown in FIGURE 4.

In operation the coolant that is fed to each disc 10 through the hollow spindles 15 spreads over the grinding surfaces 12. The cross passages 20 at the ends of radial passages 19, which receive coolant from center opening 18, are very effective in conducting coolant to peripheral areas of the disc surface 12 which were formerly inadequately supplied with coolant. Furthermore, these cross passages 20 accomplish this improved coolant distribution without markedly weakening the disc.

Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

I claim:

1. An abrasive grinding disc having a side grinding surface and a peripheral edge, comprising: means providing a coolant opening adjacent the center of said disc, a plurality of first coolant passage means formed in said disc extending from said center coolant opening to receive coolant therefrom toward but short of said peripheral edge, and a second coolant passage means at the outer end of each first coolant passage means extending transversely thereto, all said coolant passage means having open sides at said surface and all extending in essentially straight lines.

2. The disc of claim 1 wherein each said second coolant passage means lies substantially on a chord of said disc and terminates at each end short of said peripheral edge.

3. An abrasive grinding disc having a side grinding surface and a peripheral edge, comprising: means providing a coolant opening adjacent the center of said disc, a plurality of rst coolant passage means formed in said disc extending radially from said center coolant opening to receive coolant therefrom toward but short of said peripheral edge, the outer ends of said rst coolant passage means substantially lying on a circle substantially concentric with said peripheral edge, and a second coolant passage means at the outer end of each first coolant passage means extending transversely thereto substantially equal distances on opposite sides of said rst coolant passage means and each lying substantially on a chord of said disc, all said coolant passage means having open sides at said surface and all extending in essentially straight lines.

References Cited UNITED STATES PATENTS Mines 241-296 Bachulen 241-296 Tone 51-209 X Michel 51-356 Waldron 51-283 X Laverdisse 51-209 Kemman 51-267 X ROBERT C. RTORDON, Primary Examiner.

D. G. KELLY, Assislfmt Examiner. 

